Soft X-ray Absorption Spectroscopy
The X-ray absorption near edge structure (XANES) or the near edge X-ray absorption fine structure (NEXAFS) is powerful tool to investigate inner shell excitation of an atom or molecule. The photon-energy tunability of synchrotron radiation is essential for probing these core levels. Unlike the hard X-ray absorption measurements the samples are measured under ultra-high vacuum condition. One of the examples of this technique is determination of molecule orientation in organic compounds. Orientation preference of molecule was determined by carbon NEXAFS spectra with help of the linear polarization nature of synchrotron radiation.
The π* resonance peaks for Carbon NEXAFS spectra are enhanced with 65 degree incidence angle and σ* resonances are diminished. NEXAFS spectra reveals that the PTCDA film is flat on the TiO2 (110) surface. Data measured at the VLSPGM beamline.
Each element has its own set of core levels that occur at characteristic energies. The photon-energy tunability of synchrotron radiation is essential for probing these core levels. For examples, absorption of transition metals (L-edges), oxygen (K-edge), nitrogen (K-edge), and carbon (K-edge) can be investigated. A total-electron-yield method is used for soft x-ray absorption spectroscopy measurements at CAMD.
Supported beamlines: VLSPGM Beamline for 180 – 900 eV Click for more technical information
5m-TGM Beamline for 25 – 240 eV Click for more technical information
Research/Technical Contact: Orhan Kizilkaya